1. Field of the Invention
The invention relates to pontoons, such as those used in marsh buggies, as well as guide channel systems which surround portions of a pontoon and serve as a guide for a continuous track drive train.
2. Description of Related Art
Amphibious vehicles have long been known which incorporate pontoons to provide flotation and to form a base for the mounting of equipment, men, or materials. The pontoons are usually surrounded by a cleated track system which is capable of engaging ground, water, or swamps to propel the vehicle. One or more endless chains are driven by a sprocket and surround the pontoon. The endless chains support the cleated tracks. The chains are guided along the outer surface of the pontoon by guide channels.
Designers have worked to improve the structure and integrity of the pontoon so that these vehicles are capable of working in more difficult terrain. Pontoons and guide channels are typically constructed of steel or steel alloys. The pontoons are capable of flotation and are useful for most situations where an amphibious vehicle is required. But these pontoons are also heavy and generate significant ground pressure.
Soft terrain environments which contain little free water tier flotation present a problem for amphibious vehicles. The pontoons will fail to float and track systems may become mired. In such situations, the amphibious vehicle must be able to generate low ground pressure to avoid becoming repeatedly stuck in the soft terrain.
Aluminum and aluminum alloy pontoons are ideal for such conditions as they afford a significant weight savings over and generate lower ground pressures than steel pontoons. But, because steel (including steel alloy type materials) and aluminum (including aluminum alloy type materials) are not readily combinable by welding, aluminum or nickel must be used for the guide channels on an aluminum pontoon. These channels wear down rather quickly when drive chains are operated within them. Bolts or other connection means could be used to directly connect a steel channel to an aluminum pontoon, but this would require puncturing the pontoon with a bolt, thereby weakening it and making it prone to leakage.
Steel also provides excellent reinforcement for an aluminum pontoon by strengthening the pontoon against both shear and bending forces and permitting it to be more resistent to punctures and other damage. It is, therefore, desirable to devise a method and arrangement for fixedly attaching a steel runner to an aluminum pontoon.